Facebook Messenger: Facebook Messenger is a free mobile messaging and chat app for smart phones that lets people send text messages, hold group chats, share photos or videos, and even make voice calls to their Facebook pals. This instant messaging app is available for iPhone, Android, Windows Phone, and BlackBerry phones, as well as the iPad

Main Appeal of Facebook Messenger: Freebies

One of the big draws of Facebook Messenger is that its text messages and voice calls don't count toward the monthly allowance that users have on their cell phones for voice calling or SMS texting plans. That's because messages sent with this standalone app typically go over the Internet, bypassing the carrier's cellular network. So they DO count toward any Internet data use allowance the user has, but DON'T consume any of the SMS messaging quota or voice calling minutes.

Depending on the version installed, Facebook Messenger can also switch between SMS text messaging and Facebook messaging, making it versatile and increasing the likelihood of the recipient receiving the message in real time.

Another draw is that the standalone messaging app is more focused than the general Facebook app even as Messenger offers a good number of hidden features. And the reality is that many people, especially teens and those in their twenties, use Facebook more for messaging than anything else, so they can chat with friends. The mobile Facebook Messenger app puts that function front and center on their phones, without other distracting features like Facebook's news feed or ticker.Competition in Mobile Messaging is Fierce

Facebook Messenger competes with a ton of other apps in the mobile messaging category. Messaging apps have been particularly popular in Asia, where they are used so much that they've become a primary interface to the online social experience for many millions of people. KakaoTalk (Japan), Line (South Korea) and Nimbuzz (India) are a few popular mobile messaging apps that have been trend-setters. Other standalone mobile messaging apps catching on in the U.S. include Viber, MessageMe and WhatsApp Messenger.

Other big communication platforms and apps that compete, of course, include BlackBerry Messenger and Apple's iMessage for texting, and Apple's FaceTime for video calling. Google's GChat also competes in calling. And Microsoft's Skype provides VOIP voice calling and would be a competitor, except Skype partnered with Facebook to help provide video calling on the social network's platform.Evolution of Facebook Mobile Communication

Messaging has been one of the most popular features of Facebook's social network for years, and it's undergone all kinds of name changes and user interface changes as the company poured energy into updating it.

The core function is sending an instant text message an to one of your friends on Facebook, and that function is the same regardless of whether you do it through the desktop version of the social network, the regular mobile app or standalone messaging app. Only the interface is slightly different based on which of those three versions of Facebook you're using.

Facebook's regular mobile app had built-in instant messaging capability for a long time, but in 2014 Facebook announced it was phasing out that messaging capability and requiring users to download Facebook Messenger if they wanted to do mobile instant messaging.

Typical questions people wonder about this app include: What is the point of using the separate Facebook Messenger app as opposed to the regular Facebook mobile app? Does anyone really need it? Is it any different from Facebook chat?